Children and adolescents, up to approximately age 20, are more susceptible than adults to potential health risks from chemicals and environmental hazards. Hazardous chemicals can interrupt or alter the normal development of a child's body, leading to lasting damage. Since children are smaller than adults, similar levels of exposure to toxic chemicals will have a greater effect on children compared to adults. In addition, the prevalence of chemicals in the modern era means that children today are exposed to dangerous chemicals throughout their lives, beginning in the womb. Children generally rely on adults to protect them from the risks associated with exposure to dangerous environmental agents. Through education and training, however, children and adolescents can empower themselves about the risks associated with hazardous chemicals. Once young people are aware of the threats in their everyday lives, they can take action with the adults in their schools and communities to create safer conditions. This manual will inform you about health risks associated with exposure to chemicals and environmental hazards, especially mercury, and explain what you as a student can do to promote chemical safety in your school and community. A procedure for cleaning up a mercury spill safely is appended. (Contains 4 figures, 4 tables and 15 footnotes.) [This document was prepared by Battelle Memorial Institute under contract EP-W-04-021.].